1. Field of the Invention
The present invention relates to induction cooking ovens, and more specifically to dome-shaped induction ovens wherein an induction coil heats a metal plate embedded in the floor or dome of the oven.
2. Description of Related Art
Many restaurants currently use wood burning ovens to cook pizza and other food items. These ovens are typically dome-shaped, like an igloo, are made of concrete or stone, and burn wood as a heat source. The same ovens are also typically available using gas heat under the base or inside the oven. Although gas is used as a primary heat source in these ovens, wood is often burned to flavor the food.
Although the use of wood burning ovens produces positive results in food flavoring, there are many disadvantages to a wood burning oven and also to a wood burning oven in combination with gas heat. One concern is that all available oxygen in the oven could possibly be used to burn the wood and that the gas flame would extinguish due to the lack of oxygen. In this environment, the gas would continue to flow into the oven and, after a sufficient amount of gas has accumulated, a subsequent ignition of the gas could result in an explosion. In addition, in a wood burning oven or in a wood burning oven with a gas flame, the fire source takes up cooking space and certain areas close to the heating source are not usable for cooking. In addition, it is difficult to precisely control the temperature of a wood burning oven. Although it may be desired to have an oven with different locations being heated to different temperatures, this is difficult in the wood burning oven environment. Additionally, in some areas, building code requirements prohibit the use of wood burning ovens. In these areas, restaurant owners are limited to gas-fired ovens, but in some cases are allowed to burn a limited amount of wood to flavor the food.
The use of induction heating to cook food is widely known and has been used for many years. In current induction technology, a magnetic field is created and the cooking vessel becomes the receiver in the magnetic circuit. The magnetic field causes the bottom of the cooking vessel to heat rapidly. Control of the magnetic field allows very accurate adjustment of the speed and intensity of the heat. However, for successful operation, the cooking vessel, pot or pan must have sufficient magnetic susceptibility. This limits the use of cookware for use with induction technology to pots or pans constructed of stainless steel, cast iron pans or the like. The use of inductive technology in ovens has been described in various U.S. patents, including U.S. Pat. No. 3,790,735 issued Feb. 5, 1974 to Peters, Jr. and U.S. Pat. No. 400,978 issued Apr. 9, 1889 to H. F. Watts.
In the Watts patent, a basic induction oven is described. In this embodiment, plates with magnetic susceptibility are placed in close proximity to induction coils. These plates can form either the walls of an oven or a bottom of a cooking vessel. As alternating current is generated through the induction coils to create the magnetic field, and the temperature of the plates rises rapidly. Because the plates comprise the walls of the oven or the base of the cooking vessel, this heat is then transferred to the item to be cooked. The Watts patent discloses the basics of induction cooking; however, it is limited either to ovens constructed of a magnetically susceptible metal, or to magnetically susceptible pans or cooking vessels.
The Peters, Jr., patent discloses an improved induction heated oven wherein all the walls of the oven are heated using induction technology. By heating all of the walls or sides of the oven cavity, the oven cavity is heated uniformly in a minimum time period. However, the walls or sides of the oven cavity must still be manufactured from a metal having magnetic susceptibility. The Peters, Jr., patent does suggest the use of an insulated oven cavity, but in this embodiment, a metal-based cooking utensil in which the food is placed and which can be magnetically heated must be used.
What is needed is an oven capable of exploiting the conventional technology without being limited to the inner surfaces of the oven cavity or the cooking utensil being made of a metal-based material having magnetic susceptibility. It is also desirable to burn a small amount of wood to thereby impart additional flavoring on the food. It is further desirable to include several induction plates so as to maintain differing temperature zones throughout the oven.